Field of the Invention
The present invention relates to a centrifugal filtration apparatus used to filter out impurities in a fluid and, more particularly, to a centrifugal filtration apparatus including a stereoscopic filter that is installed in a rotor and disposed in a fluid channel to efficiently come into contact with impurities in a fluid, thereby increasing impurity removal efficiency.
Description of the Related Art
A typical centrifugal filtration apparatus is an apparatus to filter, purify, or thicken a mixture of elements that have different compositions or specific gravities using centrifugal force. It is generally used as a filter to remove impurities from a fluid.
FIG. 1 is a cross-sectional view illustrating the construction of a conventional centrifugal filtration apparatus.
The centrifugal filtration apparatus of FIG. 1 is a centrifugal filtration apparatus that filters out impurities in a fluid (for example, lubricating oil) used for lubricating an engine.
The centrifugal filtration apparatus includes a shaft 10 having a fluid channel 11 therein through which a fluid passes, a rotor 20 that rotates about the shaft 10, a stand tube 30 that rotates about the shaft 10 along with the rotor 20 and sprays a fluid that is introduced through the shaft 10 into the rotor 20, and a casing 40 that has an inlet 41 and an outlet 42 and encases the rotor 20 therein.
The centrifugal filtration apparatus is supplied with a fluid by action of a pump (not shown) and filters the fluid before the fluid is supplied to an engine or other machinery.
Specifically, the rotor 20 is rotated at high speed due to reaction against spraying action of a fluid that is sprayed through a nozzle 21 formed in the rotor 20. Impurities in the fluid that is sprayed into the rotor 20 from the stand tube 30 are separated due to centrifugal force and to a difference in specific gravity between the impurities and the fluid. The separated impurities spatter and stick to a piece of paper (not shown) installed inside the rotor 20. In this way, impurities are removed.
The conventional centrifugal filtration apparatus has low filtration efficiency in removing fine particles having a size of 10 μm or less. This is because the influence of centrifugal force on fine particles having a size of 10 10 μm or less is negligible. Therefore such fine particles cannot reach a paper filter installed in the rotor 20 though centrifugal force. For this reason, it is difficult to remove particles having a size of 10 μm or less with a conventional centrifugal filtration apparatus.
In short, although conventional centrifugal filtration apparatuses have a high filtration capacity, they have a disadvantage of low removal efficiency for impurities having a size of 10 μm or less.
On the other hand, there are some filters that can pass only particles having a predetermined size or less, for example, 10 μm or less. These filters can easily filter out impurities with a size of 10 μm or less, but such filters generally have low filtration capacity. Besides, impurities that are filtered out by filters are likely to accumulate on the surface of the filters, which results in an increase in flow resistivity. This leads to the need of frequent filter replacement.